U.S. Pat. No. 3,545,202 to Batt et al. entitled "Wall Structure and Combustion Holes for a Gas Turbine Engine" and U.S. Pat. No. 3,706,203 to Goldberg et al. entitled "Wall Structure for Gas Turbine Engine" are representative of the use of convectively cooled panels in gas turbine combustion chambers. The panels confine high temperature combustion products to a defined space within the engine. Temperatures within the defined space may reach levels on the order of three thousand five hundred degrees Fahrenheit (3500.degree. F.) or higher. Cooling air is flowable between ribs of the panels to prevent deterioration of the material from which the panels are constructed.
Although the structure of such ribbed panels appears relatively simple, the fabrication thereof and molding the panels into useful shapes is often difficult. One technique for fabricating ribbed panel sheet stock is set forth in my U.S. Pat. No. 4,020,542 entitled "Sandwich Panel Fabrication", now of common assignee herewith. By the fabrication technique which I have disclosed therein, alternating sheets of rib and core material are roll bonded together and sliced to form the rib section of a panel. Top and bottom sheets of facing material are bonded to opposing sides of the rib section and the core material is subsequently leached therefrom to form the ribbed sandwich panel.
As is illustrated by the referenced patents, Batt et al and Goldberg, flat panel stock is typically rolled to a cylindrical geometry for use. Slight conical geometries are also employed. Inherent stiffness of the ribbed panels inhibits forming, particularly in the longitudinal direction of the ribs. Forming difficulties may ultimately limit the use of such panels.
Panels having increased suitability to forming and methods for manufacture thereof are sought by scientists and engineers in the industry.